I meant your CIS motor not your engine. The CIS motor opens and closes an air valve, at rest it is open. If the motor is working correctly, the engine will always start at a higher rpm (CIS motor open) and immediately drop to the set rpm when the CIS motor receives electricity and closes (or begins to control the idle rpm). If you aren't starting at a higher rpm and dropping the CIS system is not working. The CIS motor has a three contact plug (secured with a wire push bale) on one end and interrupts an air hose leading from the intake air to the intake manifold (an arrow cast into the motor indicates the direction of flow). If one of the contacts is not connected the motor will not close giving a pulsating high idle condition, the second connection opens the air flow, and the third is a ground I believe. The CIS motor can go from $10-15 on eBay used or if I remember about $75 at the dealer. You might try FCP Groton too. As long as you are easy with the electrical connection (make sure all three are making contact) and the air flow direction is correct, it is a simple do it yourself replacement. It is held in place below the intake manifold with a clamp and the hoses are attached with common hose clamps. The air leak you mention could be an air leak in the CIS hose which would also disrupt the function of the CIS system.